The invention relates to a protective arrangement, that comprises one or several essentially stiff-structured plane structures, such as protective plates, elements or like, each one of which is meant to be used advantageously with one or several similar ones, that are to be attached to each other removably, particularly for covering of ground in order to protect and/or coat the same temporarily and/or for a like purpose. A structural part, that is stiffened particularly in proportion to bending, acts as the plane structure""s supporting structure, that has stiffening ribs or like, placed in the longitudinal direction and/or in the crosswise direction or correspondingly.
For the purpose above, particularly for covering a field of grass or e.g. of ice, it is previously known to use separate surface elements, that are to be connected to each other e.g. by quick-release arrangements in order to form a uniform surface. For example covering elements being sold nowadays by the name TERRAPLAS represent particularly more developed solutions, that are made of plastics by injection moulding. The covering element in question has been manufactured as a perforated structure in a way, that not any actual thermal insulation effect may be achieved by the type of covering element. Correspondingly the support arrangement to support the covering elements on the ground must furthermore be attached to the covering elements by means of totally separate auxiliary devices and work stages. In addition to that the locking arrangements connecting the covering elements to each other must also be attached separately, so that a uniform covering may be achieved by the type of covering elements.
On the other hand it is previously known to use e.g. styrox particularly for covering of ice fields, that has been surrounded by both sides of the same by plywood plate. This type of solution is naturally not applicable to be installed as such particularly on a grass field, if not totally separate foot structures are being used to raise the covering structure apart from the ground. On the other hand when being used in connection with an ice field, such problem of this type of solution has been found, that the plywood plates tend to freeze into the ice, that is why loosening of the same is laborious. In addition to that the type of constructions are very heavy, that is why storing as well as use of the same in actual coating is disproportionately difficult.
On the other hand in the Finnish Patent Application number 964199 there has been presented a protective structure, the thermal insulation of which comprises a preferably plastic based, such as cell, cellular, foam plastic structured and/or a like thermal insulation layer, whereby a support arrangement, that is formed of the bottom surface of the same in an essentially built-in manner, comprises a platform structure projecting from the basic wall thickness of the thermal insulation layer, particularly to achieve an air space between the protective structure and the ground under the same.
The solution in question is very advantageous in practice, which is due to the fact, that the thermal insulation existing between the ground and the protective structure gets more efficient particularly thanks to the air space existing between the protective structure and the ground. In this case the feet being formed as a built-in platform structure directly to the bottom surface of the thermal insulation layer first of all prevent so called burning of the grass being left under the protective structure. In the application in question there has been presented furthermore as an advantageous embodiment coupling of the protective structures with each other by means of a joint assembly, that is arranged built-in to the same during manufacturing and that operates e.g. by quick-release principle. The solution being developed in this connection has many advantages in practice, but one disadvantage in practice is such, that when grounds of totally differing type e.g. a grass and an ice surface are being coated, also different kinds of elements must be used, that have differing structures in respect with each other for each respective use. On the other hand when speaking of protective elements to be used in connection with a grass surface, the thermal insulations are very often unnecessary in practice.
It is the aim of the protect arrangement according to this invention to achieve a decisive improvement in the problems presented above and thus to raise substantially the level of knowledge in the field. To achieve this aim, the protect arrangement according to the invention is primarily characterized in, that a protect arrangement, that is meant particularly for temporary protecting of a field of grass and/or of ice, comprises one or several preferably plastic based, such as cell, cellular, foam plastic structured or like thermal insulation assemblies, each one of which is attached or is to be attached at least to the downward side of the supporting structural part and, wherein a supporting structure is formed of the thermal insulation assembly, that projects essentially from the downward surface of the stiffening ribs or the like.
As the most important advantages of the protect arrangement according to the invention may be mentioned easy installation of those surface structures to be formed of the same as well as simplicity of construction and manufacturing of a structure according to the same. Thanks to the invention it is first of all possible to use the same structural part of the protect assembly as an advantageous embodiment as such without the thermal insulation for covering e.g. a field of grass and correspondingly for covering a field of ice, when equipped with a thermal insulation, that may be attached advantageously e.g. by a snap-on-joint to the stiffening ribs existing on the downward surface of the supporting structural part. Furthermore as an advantageous embodiment, the protect arrangement is formed of protective plates, that are coupled with each other on hinge-principle, whereby a coating composition is achieved, that may be easily rolled up. In this connection it is naturally advantageous to exploit furthermore removable couplings in connection with the hinge-joints so, that the plates may as needed be released from each other, whereby replacement e.g. of one separate protective plate with another one is enabled when necessary.
As an advantageous embodiment, to the back part of a supporting structural part being used particularly for covering a field of grass, there has been arranged advantageously a net-like, grate-like, perforated structure or like, which enables ventilation of the grass existing under the protective plate as well as other metabolism of the same. The basic principle of the invention, that a supporting structure is formed of the thermal insulation layer, that extends underneath the supporting structural part and that has when necessary furthermore a platform structure being formed in a certain way, brings out a particularly significant improvement to the comfortability of use for a surface structure entirety being formed of the protective plates. When the stiffening ribs of a protective plate, that is manufactured e.g. by extrusion or injection moulding and that is equipped with stiffening ribs and possibly also with thermal insulations on the downward side, are being placed as usual directly against the ground, direct thermal conduction always takes place from the cold ice surface by the stiffening ribs. This is why an adequate thermal insulation influence may not be achieved by traditional solutions. Thanks to the protect arrangement according to the invention, this problem may be avoided also in such a solution, in which the supporting structure of the thermal insulation does not extend to the point of the ends of the stiffening ribs, in which case there anyhow exists an insulating air space between the ends of the stiffening ribs and the ground.